About this 3D model

This is a derivation of an extension of an Arduino casing extended with a drill out for an on/off switch. (http://www.thingiverse.com/thing:31924) Thanks to DDD (http://www.thingiverse.com/DDD/overview) for this cool project. There are several versions with different diameters (12mm and 12.5mm) and a 12.5mm version with cut-out for a counter-nut.